I am currently trying to calculate drag coefficient on a cylinder using "Normal force x" and plugging that value into the equation for drag coefficient,

Cd=Fd/(phi*v^2*A*0.5)  

The coefficient calculated is coming out as 0.52 when i know it should be double that, could someone give me some pointers on where i might be going wrong?

I am completing the simulation in 2D. I am using the time dependent condition, the computational domain is as large as required, the mesh size is 7 and i have specified the cylinder as a real wall. Also initial conditions are set to 20m/s in x direction for velocity. I have also tried tutorial 7 and I am still coming to the incorrect value.

Any help is greatly appreciated, thank you.